Sea anchors have been long-known. Sea anchors can be found in the naval lore dating to the 1700's where sailing ships, under the press of wind and wave during storms, have deployed sea anchors to assist in reducing undesired motion (drifting) of the vessel through the sea in response to the wind and wave. These early sea anchors would appear to have been simply a piece of sailcloth tied to a mooring line at the four corners and deployed overboard, perhaps with weighting to assure their sinkage to "fill", so to speak, with seawater as the motion of the vessel dragged the sea anchor through the water and thereby resist drifting motion of the vessel.
The stability of sea anchors has not always been completely desirable, however. For example, a sea anchor is subject to rotational forces as the sea anchor moves through the water and in the event the rotational motion is extensive, the shroud lines by which corners of the sea anchor are attached to a mooring line can become twisted, one with the next, eventually collapsing the sea anchor.
Equally, recovery of a sea anchor has traditionally required strenuous effort since during recovery the sea anchor was being pulled against the resistance of water trapped thereby; or alternately it was necessary to take the vessel to the sea anchor for recovery. As a result of both of these certain difficulties in recovering sea anchors once deployed, and certain losses as a result of sea anchors becoming fouled and requiring jettisoning, traditionally sea anchors have often been simply regarded as expendable and configured to be unhooked and allowed to sink at sea when their use was no longer required. While such simple abandonment represents a cost in lost materials and therefore, to a certain extent, has been considered undesirable, for small vessels a more serious difficulty is associated with simple abandonment of sea anchors when the weather calms. Often these small vessels can carry only a limited number of sea anchors; and in very small vessels such as liferafts, typically only a single sea anchor can be accommodated. While abandonment of the sea anchor allows the vessel free mobility again following, for example, a storm involving severe wind and wave, should the sea anchor be abandoned, subsequent storms could cause considerable difficulty for a vessel thereby found without a replacement on board.
Accordingly, a sea anchor configured to be substantially free of opportunity for self-fouling while still readily recoverable with a minimal effort could have substantial utility in commerce. Likewise, methods for retrieving sea anchors readily and means for implementing such methods could find substantial utility in commerce.